Lintcode 两个排序数组的中位数

class Solution {
public:
/**
* @param A: An integer array.
* @param B: An integer array.
* @return: a double whose format is *.5 or *.0
*/
double findMedianSortedArrays(vector<int> A, vector<int> B) {
//int minidx = 0, maxidx = m, i, j, num1, mid = (m + n + 1) >> 1,num2;
if (A.size() > B.size()) return findMedianSortedArrays(B,A);
int m = A.size(),n = B.size();
int imin = 0,imax = m,half_len = (m + n + 1) / 2,i,j,max_of_left,min_of_right;
while (imin <= imax) {
i = (imin + imax) / 2;
j = half_len - i;
if (i < m && j > 0 && B[j - 1] > A[i]) imin = i + 1;
else if (i > 0 && j < n && B[j] < A[i - 1]) imax = i - 1;
else {
if (i == 0) max_of_left = B[j - 1];
else if (j == 0) max_of_left = A[i - 1];
else max_of_left = max(A[i - 1],B[j - 1]);
break;
}
}
if ((m + n) % 2 == 1) return max_of_left;
if (i == m) min_of_right = B[j];
else if (j == n) min_of_right = A[i];
else min_of_right = min(A[i],B[j]);
return (max_of_left + min_of_right) / 2.0;
}
};